A series of inter-related experiments is proposed, which will examine developments in children's understanding of spatial transformations from infancy through the preschool years. Children's understanding of three kinds of spatial transformations-single displacements, multiple displacements, and transpositions - will be examined from an informational perspective. This perspective focuses on what information children extract from the transformations they observe and how they use that information to determine where to search. All of the experiments are based on simple hiding-and-finding games in which children are shown objects, the objects are then hidden within a set of containers, and children search for them. The various experiments will involve systematically varying the manner in which objects are hidden and the characteristics of the search space, so as to identify specific determinants of children's search patterns. The research is expected to contribute to scientific knowledge of early cognitive development. One important contribution will consist in providing much-needed information about the transition from infancy to early childhood. Another will consist in elucidating very early phases in the development of spatial cognition. Finally, the research will contribute to an understanding of the early development of information-processing skills that are central to all of cognitive development.